The present invention relates to a display device, for example, which is applicable to the one configured to detect power supply voltage drop.
In the case where the liquid crystal display panel of the liquid crystal display device is in a power OFF state, the pixel charge will be gradually discharged, the process of which causes an afterimage. In the case where DC voltage is applied to the liquid crystal layer of the pixel for a long period of time, the liquid crystal life will be reduced. The aforementioned residual charge is required to be immediately discharged. The power OFF state is detected under observation of the power supply voltage drop. Based on the detection results, the switching transistor for each pixel of the liquid crystal display panel is turned ON simultaneously so as to discharge storage data of the pixel to the data line via the switching transistor. This may immediately clear the displayed image to remove the afterimage.
Japanese Unexamined Patent Application Publication No. 2004-226597 proposes provision of the afterimage removing circuit such as the circuit for detecting the power supply voltage drop in the liquid crystal display device for a main body of the liquid crystal display device outside the liquid crystal display panel, or in the liquid crystal display panel.